麻烦帮我化简下Cos^2(π/4-θ) / Sin(π/4+θ)
已知 sin(θ+kπ)=-2cos (θ+kπ) 求 ⑴4sinθ-2cosθ/5cosθ+3sinθ; ⑵(1/4)
若2sin(π4+α)=sin θ+cos θ,2sin2β=sin 2θ,求证:sin&
已知tan(θ+π/4)=-2,求cosθ平方+sinθcosθ-1
θ∈(0,π/2),比较cosθ、sin(cosθ)、cos(sinθ)的大小
化简sin(θ-5π)cos(π/2+θ)cos(4π-θ)/cos(3π-θ)sin(θ-3π)sin(-θ-4π)
2(sinθ+cosθ)= 2√2sin(θ+π/4)为什么?; (-π/2
已知sin(θ+kπ)=2cos[θ+(k+1)π],k∈Ζ,求4sinθ-2cosθ/5cosθ+3sinθ的值
sin(θ-5π)cos[(-π/2)-θ]cos(8π-θ)}/sin[θ-(3π/2)]sin(-θ-4π)
sin(π-θ)+cos(2π-θ)/cos(5π/2-θ)+sin(3π/2+θ)=2,则sinθcosθ=_____
已知(4sinθ-2cosθ)/(3sinθ+5cosθ)=6/11,求5cos^2θ/(sin^2θ+2sinθcos
证明下列恒等式: (1)2sin(2/π+x)cos(2/π-x)*cosθ+(2cos^2x-1)*sinθ=sin(
若(sinθ+cosθ)/(sinθ-cosθ)=2,则sin(θ-5π)*sin(3π/2-θ)等于?